Poly(arylene ethers) with pendant crosslinkable groups, and devices incorporating same

ABSTRACT

A polymer comprising units having the formula (I) 
     
       
         
         
             
             
         
       
         
         
           
             wherein: Q 1  comprises at least one aryl or heteroaryl group; Q 2  comprises at least one aryl or heteroaryl group; X 1  is O bonded directly to an aryl carbon of Q 1 ; X 2  is O bonded directly to an aryl carbon of Q 2 ; Z is a linker comprising at least one —(C(R 2 ) 2 )— group; Y is a single bond or linker group (e.g., comprising up to about 50 carbons); R 1  is independently at each occurrence H, a halogen, an alkyl group, a heteroalkyl group, an aryl group, or a heteroaryl group; R 2  is independently at each occurrence H, an alkyl group, or a heteroalkyl group; and R 3  is H or a crosslinkable group.

STATEMENT OF RELATED CASES

This application is related to the following, concurrently filed,commonly assigned U.S. patent applications, each of which isincorporated by reference: (1) U.S. Ser. No. 10/714,356 entitled“Process for Preparing Poly(arylene ethers) with Pendant CrosslinkableGroups;” now allowed (2) U.S. Ser. No. 10/714,387 entitled “CrosslinkedCompositions Comprising a Poly(arylene ether) and a Nonlinear OpticalChromophore, and Devices Incorporating Same;” (3) U.S. Ser. No.10/714,766 entitled “Process for Preparing Crosslinked Polymer BlendsThat Include a Luminescent Polymer;” now allowed and (4) Ser. No.10/714,837 and (4) “Crosslinked Polymer Blends That Include aLuminescent Polymer, and Devices Incorporating Same, now allowed.”

BACKGROUND

All patents, patent applications, and publications cited within thisapplication are incorporated herein by reference to the same extent asif each individual patent, patent application or publication wasspecifically and individually incorporated by reference.

The invention relates generally to crosslinkable polymer compositions,methods of making crosslinkable polymers, and devices and uses forcrosslinkable polymers. Crosslinked polymer compositions generally havehigher glass transition temperatures (T_(g)) and greater mechanicalstability than noncrosslinked polymers. In addition, crosslinkedpolymers are usually resistant to solvents that dissolve noncrosslinkedpolymers. The property of solvent resistance is particularly importantin applications that require overcoating of polymers with otherpolymers. The properties of crosslinked polymers including highmechanical strength, high T_(g), and solvent resistance are important inapplications such as protective coatings, electronics, optics,electro-optics, and polymer light emitting diodes.

Poly(arylene ether)s having hydroxy, cyclopentadienone, acrylate, andalkynyl crosslinkable groups in the main chain and/or side-chain(pendant) are known, for example see U.S. Pat. Nos. 6,340,528;6,313,185; 6,117,967; 6,060,170; 5,994,425; 5,849,809; 5,498,803; and5,204,416. In some cases, functional groups have been grafted ontopoly(arylene ether)s under conditions requiring long reaction times. Inother cases, functional groups on the poly(arylene ether) backbone wereconverted into other functional groups under reaction conditions such asreduction or lithiation/carbonyl addition, which may limit the possiblemonomers or pendant groups to structures that are not reactive underthose conditions.

SUMMARY

One embodiment is a polymer comprising units having the formula (I)

wherein: Q¹ comprises at least one aryl or heteroaryl group; Q²comprises at least one aryl or heteroaryl group; X¹ is O bonded directlyto an aryl carbon of Q¹; X² is O bonded directly to an aryl carbon ofQ²; Z is a linker comprising at least one —C(R²)₂)— group; Y is a singlebond or linker group (e.g., comprising up to about 50 carbons); R¹ isindependently at each occurrence H, a halogen, an alkyl group, aheteroalkyl group, an aryl group, or a heteroaryl group; R² isindependently at each occurrence H, an alkyl group, or a heteroalkylgroup; and R³ is H or a crosslinkable group. The crosslinkable group maybe chosen from any crosslinkable groups that are activated chemically,thermally, or photochemically.

Another embodiment is a process comprising: a) reacting a diphenolmonomer A with a monomer B having two locations for reaction with A toform arylene ether monomer C and b) reacting arylene ether monomer Cwith a diphenol monomer D to form a polymer, where monomer A isHX¹-Q¹-X¹H  (II)

monomer B is

arylene ether monomer C is

and monomer D is

wherein Q¹, Q², X¹, X², Z, Y, R¹, and R² are as described above and L isa leaving group. The process provides polymers of structure (I) that arehighly regular and free of blockiness.

Another embodiment is a composition made by a process comprising a)providing a precursor composition comprising a polymer of structure (I)

and b) crosslinking the polymer, wherein Q¹, Q², X¹, X², Z, Y, R¹, R²,and R³ are as described above. Crosslinking may be accomplished byreaction of an R³ crosslinking group with another R³ crosslinking groupor with additives that react with the R³ groups. Other embodiments areoptical devices comprising these compositions.

Another embodiment is a composition made by a process comprising a)providing a precursor composition comprising a nonlinear opticalchromophore having the structure D-π-A and polymer of structure (I)

and b) crosslinking the polymer, wherein: D is a donor, π is a p-bridge,A is an acceptor, and Q¹, Q², X¹, X², Z, Y, R¹, R², and are as describedabove. Preferably, the process further comprises applying an electricfield to effect poling. The electric field may be applied using contactpoling or corona poling. The poling may begin before crosslinking,during crosslinking, or after crosslinking. Other embodiments areelectro-optic devices made from the compositions.

Another embodiment is a process comprising a) providing a polymer blendcomprising a luminescent polymer and a second polymer, where at leastone of the polymers is crosslinkable, and b) crosslinking thecrosslinkable polymer. As used herein, a “polymer blend” is amacroscopically homogeneous mixture of two or more different species ofpolymer, as recited in Jenkins, A. D. et al., IUPAC Glossary of BasicTerms in Polymer Science, Pure Appl. Chem. 1996, 68(12), 2287–2311. Insome embodiments, both polymers are crosslinkable. Other embodiments arepolymer blends comprising a luminescent polymer and a second polymer,where at least one of the polymers is crosslinked. Additionalembodiments include light emitting devices comprising the crosslinkedcompositions.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a general scheme for preparing poly(arylene ether)s.

FIG. 2 illustrates a process for preparing functionalized aryleneethers.

FIG. 3 illustrates exemplary donors for nonlinear optical chromophores.

FIG. 4 illustrates exemplary acceptors for nonlinear opticalchromophores.

FIGS. 5–6 outline the synthesis of a crosslinkable poly(arylene ether).

FIG. 7 illustrates useful polymers and chromophores.

FIG. 8 is a graph comparing electroluminescent performance.

The reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

In one embodiment, a poly(arylene ether) polymer comprises units havingthe formula (I)

wherein: Q¹ comprises at least one aryl or heteroaryl group; Q²comprises at least one aryl or heteroaryl group; X¹ is O bonded directlyto an aryl carbon of Q¹; X² is O bonded directly to an aryl carbon ofQ²; Z is a linker comprising at least one —C(R²)₂)— group; Y is a singlebond or linker group (e.g., comprising up to about 50 carbons); R¹ isindependently at each occurrence H, a halogen, an alkyl group, aheteroalkyl group, an aryl group, or a heteroaryl group; R² isindependently at each occurrence H, an alkyl group, or a heteroalkylgroup; and R³ is H or a crosslinkable group. In some embodiments, Q¹comprises a polycyclic aromatic ring system or a polycyclicheteroaromatic ring system. In many embodiments, Q¹ comprises at leasttwo aryl or heteroaryl groups. Preferably, the linker between the firstaryl or heteroaryl group and the second aryl or heteroaryl group is amethylenediphenyl group in which the methylene carbon is bonded to atleast two phenyl groups. Typically, the methylenediphenyl grouporiginates from a bisphenol monomer. Bisphenols are compounds made bycondensing one equivalent of an aldehyde or ketone with two equivalentsof a phenol. Consequently, both the phenyl and methylene moiety of themethylenediphenyl group can be substituted with a variety ofheteroatoms, alkyl groups, heteroalkyl groups, aryl groups, orheteroaryl groups. When structurally feasible, the substituents on themethylene group of the methylenediphenyl group can be bonded to eachother to form one or more rings. The diphenyl groups of the methylenediphenyl group may also be joined together to form a ring. Some examplesof methylenediphenyl groups are

Referring to structure (I), Y is a single bond or a linker group. Thelinker group can be any chemical group that can withstand thepolymerization conditions and allows the monomer to undergonucleophilic, phenolic aromatic substitutions on the phenyl rings bondedto Y. Preferably, Y is a single bond and R¹ is F at each position on thephenyl rings bonded to Y. In some embodiments, Y comprises a singlebond, an alkene or an alkyne group. In other embodiments, Y comprises aketone, a sulfone, or a phosphine oxide group. The ketone, sulfone, orphosphine oxide group may be part of a linear chemical group or part ofa ring that is conjugated to the phenyl rings bonded to Y. Preferably,the ketone, sulfone, or phosphine oxide group is bonded directly to thephenyl rings bonded to Y, i.e., Y is preferably

Referring again to structure (I), Q² may be a 6-membered aromatic orheteroaromatic ring, a polycyclic aromatic ring system, or a polycyclicheteroaromatic ring system provided that the ring or ring system iscapable of forming a bond with both X² atoms and the Z linker group.Preferably, Q² comprises a phenyl ring to which both X² oxygen atoms arebonded, i.e. Q² comprises

When Q² comprises a phenyl ring to which both X² oxygen atoms arebonded, the oxygen atoms may be substituted para, meta, or ortho to eachother. The linker group Z may be bonded to any atom in the ring and mayfurther comprise heteroatoms, heteroalkyl groups, aryl groups, orheteroaryl groups. In many embodiments, linker group Z is —(CH₂)_(n)— or—(OCH₂CH₂)_(n)— having n=1 to 10.

In some embodiments, R³ is a crosslinkable group. In general,crosslinkable groups comprise functional groups that react to form bondsunder certain conditions. The crosslinkable group may react withcrosslinkable groups on another polymer chain or with additives (e.g.,diepoxides, diisocyantes, diisothiocyantes, and the like). Thecrosslinkable group may be chosen from any crosslinkable groups that areactivated chemically, thermally, or photochemically. Photochemicalactivation may be through either a photoradical or photoacid. An alcoholof the polymer (e.g., R³═H) may serve as a crosslinking group. Thecrosslinkable group may be attached to the monomer beforepolymerization, provided that no undesirable reaction occurs with thecrosslinker during polymerization. The crosslinker may also be graftedonto polymer by any reaction between a functional group on the polymerand the crosslinker. Examples of such reactions are nucleophilicsubstitution or addition, etherification, or esterification with analcohol on the polymer (e.g., R³═H). For example, the crosslinkablegroup may be functionalized with a carboxylic acid that may be graftedonto the polymer using a chemical reagent that converts the acid into anacylating agent in situ. Examples of such reagents aredicyclohexylcarbodiimide/dimethylaminopyridine (DCC/DMAP), a2-chloropyridinium ion, and the like (see Carey and Sundberg AdvancedOrganic Chemistry Part B: Reactions and Synthesis, Third Edition, PlenumPress, New York, p 145–151 and others). Alternatively, the crosslinkablegroup may be functionalized with a carboxylic acid chloride, which canreact with the alcohol polymer with the assistance of a base such aspyridine. Crosslinkable groups functionalized with a phenol may begrafted onto the polymer by the Mitsonobu reaction. Functional groups onthe polymer may also be converted into other functional groups that canfunction as a site for grafting crosslinkers onto the polymer. Theresulting functional groups may also be used as crosslinkable groupsthemselves. One such example is conversion of an alcohol on the polymer(e.g., when R³═H) to an ester/acid by reaction with a cyclic anhydridesuch as succinic anhydride, phthalic anhydride, and the like. Thecarboxylic acid can be used to attach crosslinkers or can be used as acrosslinker itself by using additives such as diepoxides and the like,For examples, see U.S. Pat. Nos. 5,776,378; 4,859,758; and 4,539,340.Preferably, the crosslinkable group is one that can be crosslinked bymethods known in the art, such as: a) by photoradical generators such as1-hydroxycyclohexylphenyl ketone, acetophenon dimethylketal orbenzoylmethyl ether and the like; b) by direct UV dimerization such ascoumarins (U.S. Pat. No. 6,423,818 B1) or cinnamates (U.S. Pat. No.5,484,821); and c) by thermal reactions such as with aryl trifluorovinylethers and benzocyclobutenes. Examples of such crosslinkable groups are

In one embodiment, Q¹ comprises a methylenediphenyl group in which themethylene carbon is bonded to at least two phenyl groups; Q² comprises aphenyl ring to which both X² oxygen atoms are bonded; Y is a singlebond; and Z is —CH₂—. In this embodiment, R¹ at each occurrence on thephenyl ring bonded to Y is preferably fluorine. In another preferredembodiment, R³ comprises an aryl trifluorovinyl ether. In anotherembodiment, the methylene of Q¹ is substituted with at least threephenyl groups.

In general, referring to FIG. 1, polymers comprising units havingformula (I) can be prepared by reacting about 1 equivalent of a compound1 having at least two nucleophilic aromatic leaving substituents (L)with about 0.5 equivalents of a diphenol 2 and about 0.5 equivalents ofa diphenol functionalized with an aliphatic alcohol 3. A nucleophilicaromatic leaving substituent is a moiety that can act as a leaving groupin an aromatic substitution reaction. A nucleophilic aromatic leavingsubstituent can be a single atom or a group of atoms, for example see F.A. Carey and R. J. Sundberg Advanced Organic Chemistry, Part A, 3^(rd)ed. 1990, pp 579–583. If one of the diphenol compounds 2 or 3 is morereactive, the resulting polymer may have blocks resulting from reactionof 1 with the more reactive diphenol to give an oligomer, followed byreaction with the less reactive diphenol to give a block copolymer. Someapplications, such as low loss optical polymers, may favor a copolymerwithout blocks (i.e., a polymer that has substantially the structure in(I) throughout the polymer chain). The inventors have found thatblockiness resulting from reactivity differences in the monomers can beovercome by a) reacting diphenol monomer A with monomer B to givemonomer C with structure B-A-B, wherein monomer B has at least two sitesfor reacting with monomer A, and b) reacting diphenol monomer C withanother monomer D to give a polymer. Referring to FIG. 2, monomer A isHX¹-Q¹-X¹H  (II)

monomer B is

monomer C is

and monomer D is

wherein Q¹, Q², X¹, X², Z, Y, R¹, and R² are as described above and L isa nucleophilic aromatic leaving substituent. Preferably, referring tostructure (II), Q¹ comprises a methylenediphenyl group, e.g., (II) is abisphenol. L may be a halogen, nitro group, or phenylsulfonyl group.Preferably, L is fluorine. In one embodiment, reacting monomer A withmonomer B comprises heating a mixture of monomer A and monomer B in adipolar aprotic solvent to at least 110° C. Dipolar aprotic solvents areknown in the art and include dimethylformamide (DMF) anddimethylacetamide (DMAC). Another embodiment of the process furthercomprises cooling the reaction mixture of monomer A and monomer B aftermonomer C is formed and before monomer D is reacted with monomer C.Preferably, reacting monomer C with monomer D to form a polymercomprises heating a mixture of monomer C and monomer D in a dipolaraprotic solvent to at least 110° C., thereby providing a polymersolution. In one useful embodiment, the process further comprisesfiltering the polymer solution while the temperature of the polymersolution is greater than about 80° C. Such filtering removes most of theinorganic salts while ensuring the solubility of the polymer in thefiltrate. In another embodiment, monomer A is

monomer B is

monomer C is

and monomer D isHX¹-Q¹-X¹H  (II)

wherein Q¹, Q², X¹, X², Z, Y, L, R¹, and R² are as described above.

The compositions made from the crosslinkable polyarylene ethersdescribed above may be useful in variety of applications including low kdielectrics and passive optical components. Another embodiment is acomposition made by a process comprising a) providing precursorcomposition comprising a polymer having units with the formula (I)

and b) crosslinking the polymer, wherein Q¹, Q², X¹, X², Z, Y, R¹, R²,and R³ are as described above. The precursor composition may be providedby known methods including spin coating, dip coating, brushing, printing(e.g., ink jet printing), and the like. Crosslinking may be accomplishedby reaction of an R³ crosslinking group with another R³ crosslinkinggroup or with additives that react with the R³ groups. When R³ is H,additives that react with alcohols can effect crosslinking (for example,diepoxides, diisocyanates, or diisothiocyanates). The crosslinking maybe initiated thermally, chemically, or photochemically (e.g., by actinicradiation). The actinic radiation may crosslink two R³ groups directlyby dimerization or may produce a photoacid or photoradical crosslinkingcatalyst, for example see U.S. Pat. Nos. 6,555,288 and 6,020,508.Preferably, crosslinking the polymer comprises heating to at least about200° C.

The fabrication of devices comprising optical waveguides includingpolymers is well documented, for example see U.S. Pat. No. 6,306,563. Atypical optical waveguide comprises clad layers surrounding awaveguiding core. The refractive index of the clad layers is lower thanthe refractive index of the core. The crosslinked compositions describedabove have low optical loss and are useful for fabricating waveguideoptical devices with enhanced performance. Another embodiment is adevice including a waveguide comprising the crosslinked compositionsdescribed above. The crosslinked compositions may be used as the cladand/or the core. Preferably, the waveguide core and at least one cladcomprise the crosslinked compositions.

Another embodiment is a composition made by a process comprising a)providing a precursor composition comprising a nonlinear opticalchromophore having the structure D-π-A and polymer of structure (I)

and b) crosslinking the polymer, wherein: D is a donor, π is a p-bridge,A is an acceptor, and Q¹, Q², X¹, X², Z, Y, R¹, R², and R³ are asdescribed above. The precursor composition may be provided by knownmethods including spin coating, dip coating, brushing, printing (e.g.,ink jet printing), and the like. Preferably, the process furthercomprises applying an electric field to effect poling. Poling induceselectro-optic activity in the polymer. The electric field may be appliedusing contact poling or corona poling. The poling may begin beforecrosslinking, during crosslinking, or after crosslinking, for examplesee co-pending, commonly assigned U.S. patent application Ser. No.10/301,978. The donor moiety D can comprise any of the structures shownin FIG. 3, wherein independently at each occurrence: R⁴ is H, an alkyl,an aryl, a heteroalkyl group, or a heteroaryl group; R⁵ is H, a halogenexcept when bonded to a carbon alpha to or directly to a nitrogen, O, S,an alkyl group, an aryl group, a heteroalkyl group, or a heteroarylgroup; Y is O, S or Se; m is 2, 3 or 4; p is 0, 1 or 2; and q is 0 or 1.Acceptor moiety A can comprise any of the structures shown in FIG. 4,wherein independently at each occurrence, R⁵ is H, a halogen except whenbonded to a carbon alpha to or directly to a nitrogen, O, S, an alkylgroup, an aryl group, a heteroalkyl group, or a heteroaryl group and Yis O, S or Se. In some embodiments, π comprises a thiophene ring havingoxygen atoms bonded directly to the 3 and 4 positions of the thiophenering. Preferably, the oxygen atoms are independently substituted with analkyl, heteroalkyl, aryl, or heteroaryl group. An example of a π-bridgecomprising a thiophene ring having oxygen atoms bonded directly to the 3and 4 positions of the thiophene ring is

wherein, independently at each occurrence, X is O or S and R⁶ is analkyl, aryl, heteroalkyl, or heteroaryl group. Preferably, D is selectedfrom the group consisting of

wherein, independently at each occurrence, R⁴ is H, an alkyl group, anaryl group, a heteroalkyl group, or a heteroaryl group and R⁵ is H, ahalogen except when bonded to a carbon alpha to or directly to anitrogen, O, S, an alkyl group, an aryl group, a heteroalkyl group, or aheteroaryl group. Preferably, each X is O and each R⁶ is an alkyl group.In another preferred embodiment, R³ comprises a fluorinated crosslinkinggroup and at least one of R⁴ or R⁵ comprises a fluorinated crosslinkinggroup. An example of a suitable fluorinated crosslinking group is

When the crosslinked compositions described above are electro-optic,electro-optic polymer devices comprising the compositions have enhancedproperties over conventional electro-optic polymer devices due to anincrease in thermal stability from the crosslinking. Thus, anotherembodiment is an electro-optic device comprising the crosslinkedcomposition described above. The electro-optic device may be an opticalmodulator, an optical switch, or an optical directional coupler.Preferably, the electro-optic device comprises: 1) an input waveguide;2) an output waveguide; 3) a first leg having a first end and a secondend, the first leg being coupled to the input waveguide at the first endand to the output waveguide at the second end; and 4) a second leghaving a first end and a second end, the second leg being coupled to theinput waveguide at the first end and to the output waveguide at thesecond end. Another embodiment is an electro-optic device comprising: 1)an input; 2) an output; 3) a first waveguide extending between the inputand output; and 4) a second waveguide aligned to the first waveguide andpositioned for evanescent coupling to the first waveguide. Manytelecommunication systems can be manufactured from the electro-opticdevices described above. The systems can include optical routers andphased array radars. Other embodiments include a method of datatransmission comprising transmitting light through the electro-opticcomposition described above, a method of telecommunication comprisingtransmitting light through the electro-optic composition describedabove, a method of transmitting light comprising directing light throughor via the electro-optic composition described above, and a method ofrouting light through an optical system comprising transmitting lightthrough or via the electro-optic composition described above.

Another embodiment is a process comprising a) providing a polymer blendcomprising two polymers, wherein at least one polymer is crosslinkableand at least one polymer is luminescent and b) crosslinking thecrosslinkable polymer. Both polymers may be crosslinkable. Crosslinkableluminescent polymers are known, for examples see U.S. Pat. No. 5,708,130and Muller, C. D., et al. Nature 2003, 421 (6925), 829–833. The blendcomprising two polymers may be provided by methods including dissolvingthe two polymers to make a solution and then depositing them by methodsknown to those skilled in the art like spin-coating, dip-coating,brushing, or printing (e.g., ink-jet printing). In many embodiments, theluminescent polymer comprises a polyfluorene, a polyphenylenevinylene,or a polybiphenyl. Preferably, the luminescent polymer further comprisesa charge transporter. The charge transporter may be a hole transporteror an electron transporter. The luminescent polymer may also containboth a hole transporter and an electron transporter. Some exemplarycharge transporters are triarylamines, carbazoles, a2,3-diphenylquinoxalines, and 1,3,4-oxadiazoles. Preferably, thecrosslinkable polymer comprises the structure

wherein Q¹, Q², X¹, X², Z, Y, R¹, R² and R³ are as described above.Preferably, R³ comprises an aryl trifluorovinyl ether. In manyembodiments, the crosslinking is effected thermally, chemically, orphotochemically.

Another embodiment is a luminescent composition comprising a polymerblend including a luminescent polymer and a second polymer, wherein atleast one polymer is crosslinked. Preferably, the second polymer iscrosslinked. In other embodiments, the luminescent polymer iscrosslinked or both the luminescent polymer and the second polymer arecrosslinked. The luminescent polymer may comprise a polyfluorene, apoly(phenylenevinylene), or a polybiphenyl. Preferably, the polymer thatis luminescent further comprises a charge transporter. Examples ofcharge transporters are triarylamines, a carbazoles, a2,3-diphenylquinoxalines, a 1,3,4-oxadiazoles.

In many embodiments, the crosslinked polymer comprises units having theformula

wherein Q¹; Q²; X¹; X²; Z; Y; R¹; and R² are as defined above and R⁷comprises crosslinked group. The crosslinked group R⁷ is derived from acrosslinking group that has been crosslinked. R⁷ may be derived from anacrylate, a cinnamate, an aryl trifluorovinyl ether, or abenzocyclobutene. Preferably, R⁷ is derived from an aryl trifluorovinylether. Another embodiment is a device comprising a light emittingelement, wherein the light emitting element comprises the luminescentcomposition described above. The light-emitting element may furthercomprise a charge injection layer. Charge injection layers typicallyhave energy levels that are between the relevant energy levels of areference electrode and a luminescent polymer. Preferably, the lightemitting element further comprises a hole injection layer. Holeinjection layers may comprise poly(3,4-ethylenedioxythiophene),poly(N-vinylcarbazole), polyaniline, orN,N′-diphenyl-N,N′-bis(3-methylphenyl)1,1′-biphenyl-4,4′-diamine. Inother embodiments, the light emitting element further comprises anelectron injection layer. Electron injection layers may comprise anoxadiazole, a benzobisazole, or a quinoxaline.

The luminescent compositions described above are useful, whencrosslinked, in light emitting diodes and provide advantages overnoncrosslinked light emitting polymer blends. To fabricate the lightemitting diode, a light emitting polymer and a crosslinkable polymer, asdescribed above, can be mixed to the desired ratio in a desired solvent.The solution may be spin coated on a substrate, which usually comprisesan electrode. The solvent is evaporated and the films are crosslinked.Other polymers or metal electrodes can be deposited on the crosslinkedfilms. Devices comprising the composition described above show enhancedperformance over typical polymer light emitting diodes. Thus, anotherembodiment is a device comprising a light emitting element, wherein thelight emitting element comprises the polymer blend described above. Thelight emitting element may further comprises a hole injection layer.Exemplary hole injection layers include those comprisingpoly(3,4-ethylenedioxythiophene), poly(N-vinylcarbazole), polyaniline,or N,N′-diphenyl-N,N′-bis(3-methylphenyl) 1,1′-biphenyl-4,4′-diamine. Inother embodiments, the light emitting element further comprises anelectron injection layer. Exemplary electron injection layers includethose that comprise an oxadiazole, a benzobisazole, or a quinoxaline.

EXAMPLES

The following example(s) is illustrative and does not limit the claims.

Example 1

Referring to FIG. 5, Decafluorobiphenyl (100 g, 0.3 mole),4,4′-(1-phenylethylidene)bisphenol (43.55 g, 0.15 mole) and 26 g ofK₂CO₃ were added to a 1 L round bottom flask, followed by 400 mL ofN,N-dimethylacetamide (99.9%, anhydrous). The bath temperature wasramped from room temperature to 120° C. in 1 hour. The reaction wasstirred at 120° C. for 20 h. The temperature was cooled to 105° C. over1 h to provide 10, at which point 3,5-dihydroxybenzylalcohol (21.02 g,0.15 mole) was added along with 20 g of K₂CO₃. Over the course of 3 h,the bath temperature was ramped up to 115° C. and the flask contentsallowed to react for one additional hour at 115° C. The reaction mixturewas then removed from the heat and filtered through a frit while stillhot. 50 mL of THF was used to wash remaining polymer through the frit.The solution was cooled to room temperature, and transferred to adropping funnel. The solution was added dropwise to a mixture of 750 mLmethanol-200 mL DI H₂O in a blender. The solid was collected on a frit,and dried in the air overnight. The solid was then taken up in 250 mL ofTHF, forming a viscous solution. It was transferred to a dropping funneland added dropwise to a solution of 500 ml methanol-200 ml DI H₂O. Thesolid was collected and air-dried on the frit for at least 5 hours. Thesolid was then heated at 80° C. at 87 torr on a rotary evaporator for 5hours. The product 11, a fine white powder, was isolated in 30% yield(114 g).

Referring to FIG. 5, 350 mL of anhydrous N-methylpyrrolidone wastransferred into a 1 L one neck round bottom flask containing 11 (44.3g). Drisolv grade pyridine (100 mL) was added. The mixture was stirredat room temperature for one hour, then 20.0 g (0.085 mole) of4-trifluorovinyloxybenzoyl chloride, 12, was added to the solution. Thesolution was stirred, under a nitrogen purge, for 20 h. The color of thesolution changed from light yellow to brown. The reaction was droppedslowly into a solution of methanol (500 ml) and deionized water (200 ml)in a blender. The precipitate was filtered on a glass fritted funnel(coarse). Under the given dilutions, there was a reasonable amount ofemulsified polymer in the filtrate, showing some amount offractionation. The collected solid was washed with methanol (˜2 L),which further removed some of the existing yellow color. The resultingsolid was dried on the frit in air for 48 h. The solid was thentransferred to a 1 L beaker, and 250 mL of THF was added. Once thepolymer dissolved (˜30 min), it was transferred to a dropping funnel. Itwas added dropwise to a solution of methanol (750 mL) and water (200 mL)in a blender. Solid was collected on the frit, washed with additionalmethanol (˜2 L) and air dried on the frit (with vacuum) for ˜4 h. Thesolid was again dissolved in 250 mL of THF, and dropped into 750mlMeOH/200 ml DI water while stirring in a blender. The solid wascollected and dried overnight. Finally, the solid was taken up in 250 mlof THF and dropped into 700 ml MeOH/250 ml DI water. The solid wasplaced in a 1 L round bottom flask, and placed on a rotary evaporator(60° C., 10 Torr) for 4 h to give 40.0 g of 13 as a white powder.

Referring to FIG. 6, decafluorobiphenyl (56.12 g, 0.168),2,2′-bis(4-hydroxyphenyl) hexafluoropropane (28.25 g, 0.084 mole), and3,5-dihydroxybenzylalcohol (11.77 g, 0.084 mole) were added to a 500 mLround bottom flask, followed by 250 mL of N,N-dimethylacetamide (99.9%,anhydrous). The mixture was stirred at room temperature for 45 min in sothat all of the components were completely dissolved. Next, potassiumcarbonate (51.14 g, 0.37 mole) was added and the flask placed into apreset 50° C. oil bath for 45 minutes. Afterwards, the flask was movedinto a preset 100° C. bath, while stirring and keeping the temperatureconstant for 65 min. The reaction mixture was then removed from the heatand filtered through a frit while still hot. The solution was cooled toroom temperature, and transferred to a dropping funnel. The solution wasadded dropwise to a mixture of 400 mL methanol-100 mL DI H₂O in ablender. The solid was collected on a frit, and dried in the airovernight. The solid was taken up in 250 mL of THF, forming a viscoussolution. It was then transferred to a dropping funnel and addeddropwise to a solution of 400 ml methanol-100 ml DI H₂O. The solid wascollected and air-dried on the frit overnight. The solid was heated at80° C. at 80 torr on a rotary evaporator for 5 hours. The product 14, awhite powder, was isolated in 40% yield (42 g).

Referring to FIG. 6, 20 mL of anhydrous N-methylpyrrolidone wastransferred into a 100 ml one-neck round bottom flask containing 14 (10g). Drisolv grade pyridine (3 mL) was added. The mixture was stirred atroom temperature for one hour at which point the entire solid wasdissolved. 8.0 ml of 4-trifluorovinyloxybenzoyl chloride, 12, was addedto the solution. The solution was stirred, under a nitrogen purge, for43 h. The color of the solution changed from light yellow to brown. Thereaction mixture (viscous solution) was transferred to a droppingfunnel. The solution was added dropwise to a solution of 75 ml MeOH/25ml H₂O. The solid was collected on a frit, and air-dried. The solid wastaken up in 25 ml of THF, and added dropwise to a solution of 75 mlMeOH/25 ml H₂O. The product 15 was collected, and the precipitation wasrepeated one additional time, yielding 5.2 g of solid.

Example 2

In this example, a film of polymer 13 was provided and crosslinked. Asolution of about 30% by wt. of polymer 13 in cyclopentanone wasfiltered through a 0.2 μm nylon filter and spin coated on a 6-inchsilicon wafer having a 15 μm SiO_(x) surface. The polymer was baked at150° C. under N₂ to help remove the solvent. The thickness of theresulting film was 4.0 μm. The film was then heated at 220° C. for 30min under N₂ and cooled to room temperature. The average optical loss offive measured points was 0.77 dB/cm. The film was resistant to a varietyof solvents.

Example 3

In this example, a film of polymer 16 (FIG. 7) was provided andcrosslinked. Polymer 16 was prepared in a similar manner as polymer 13,except bisphenol A was used in place of4,4′-(1-phenylethylidene)bisphenol). A solution of about 30% by wt. ofpolymer 16 in cyclopentanone was filtered through a 0.2 μm nylon filterand spin coated on a 6-inch silicon wafer having a 15 μm SiO_(x)surface. The polymer was baked at 150° C. under N₂ to help remove thesolvent. The thickness of the resulting film was 2.9 μm. The film wasthen heated at 220° C. for 30 min under N₂ and cooled to roomtemperature. The average optical loss of five measured points was 0.62dB/cm. The film was resistant to a variety of solvents.

Example 4

In this example, a polymer film of a nonlinear optical D-π-A chromophoreand polymer 13 was provided and poled. Compound 17 (FIG. 7) was thenonlinear optical chromophore, and was prepared as described incopending, commonly assigned U.S. patent application Ser. No.10/301,978. A 30% by wt. solution of 17 and polymer 13 in cyclopentanonewas spin coated on 2″ glass wafers coated with indium tin oxide (ITO)(˜30% by wt. solution of total solids with respect to cyclopentanone;the chromophore was loaded at 15% by wt. with respect to the polymer).The wafer was soft baked at 100° C. under N₂ to help remove theremaining solvent from the film. A corona voltage of 5 kV was applied tothe film while it was heated to 220° C. over 10 min (t=0). The film wasmaintained at 220° C. for 40 min while the voltage was increased to 5.5kV, 6.5 kV, and 7.5 kV at t=15 min, t=23 min, and t=30 min,respectively. At t=40 the wafer was brought to room temperature overabout 10 min under the 7.5 kV field. The r₃₃ of the film was 24 pm/V(measured at 1310 nm by the Teng-Man method).

Example 5

In this example, a composition comprising a light-emitting polymer (LEP)and a crosslinkable polymer is provided. The light-emitting polymer usedwas ADS111RE from American Dye Source (polymer 18, FIG. 7). A 3% totalsolids by wt. solution of polymer 18 and polymer 13 in cyclopentanonewas spin coated on a 2″ glass wafer covered with ITO (the ratio ofpolymer 18 to the polymer 13 was 50/50 (wt./wt.)). The film was heatedat 150° C., and then heated at 220° C. under N₂. The resultingcrosslinked blend film thickness was 100 nm and was solvent resistant.In order to complete the fabrication of the polymer light emitting diode(50/50 LEP Blend), an aluminum electrode was e-beam evaporated onto thepolymer.

For the purpose of comparison, an light emitting device (100% LEP) wasfabricated using only polymer 18. The light-current-voltage (L-I-V)curves for the 50/50 LEP Blend device and 100% LEP device are plotted onthe same scale in FIG. 8. The aluminum electrode was biased as theelectron source and the ITO acts as the hole source. A definite increasein luminance and current is observed for 50/50 LEP Blend device over the100% LEP device for most of the operating range.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

1. A composition made by a process comprising a) providing a precursor composition comprising a polymer and b) crosslinking the polymer, wherein: the polymer comprises units having the formula

 wherein: Q¹ comprises at least one aryl or heteroaryl group; Q² comprises at least one aryl or heteroaryl group; X¹ is O bonded directly to an aryl carbon of Q¹; X² is O bonded directly to an aryl carbon of Q²; Z is a linker comprising at least one —(C(R²)₂)— group; Y is a single bond or a linker group; R¹ is independently at each occurrence H, a halogen, an alkyl group, a heteroalkyl group, an aryl group, or a heteroaryl group; R² is independently at each occurrence H, an alkyl group, or a heteroalkyl group; and R³ is H or a crosslinkable group.
 2. The composition of claim 1, wherein Q¹ comprises at least two aryl or heteroaryl groups.
 3. The composition of claim 2, wherein Q¹ comprises a methylenediphenyl group in which the methylene carbon is bonded to at least two phenyl groups.
 4. The composition of claim 3, wherein Q¹ is selected from the group consisting of


5. The composition of claim 1, wherein Q¹ comprises a polycyclic aromatic ring system or a polycyclic heteroaromatic ring system.
 6. The composition of claim 1, wherein Y is a single bond, an alkene or an alkyne group.
 7. The composition of claim 1, wherein Y is a ketone, a sulfone, or a phosphine oxide group.
 8. The composition of claim 7, wherein Y is selected from the group consisting of


9. The composition of claim 1, wherein Q² comprises a 6-membered aromatic or heteroaromatic ring, a polycyclic aromatic ring system, or a polycyclic heteroaromatic ring system.
 10. The composition of claim 9, wherein Q² comprises


11. The composition of claim 1, wherein Z is —(CH₂)_(n)— or —(CH₂CH₂O)_(n)—, wherein n=1 to
 10. 12. The composition of claim 1, wherein R³ is selected from the group consisting of


13. The composition of claim 1, wherein: Q¹ comprises a methylenediphenyl group in which the methylene carbon is bonded to at least two phenyl groups; Q² comprises a phenyl ring; Y is a single bond; and Z is —CH²—.
 14. The composition of claim 13, wherein R¹ is fluorine.
 15. The composition of claim 13, wherein R³ comprises an aryl trifluorovinyl ether.
 16. The composition of claim 15, wherein crosslinking the polymer comprises heating to at least about 200° C.
 17. The composition of claim 13, wherein the methylene carbon of Q¹ is bonded to at least three phenyl rings.
 18. The composition of claim 1, wherein the precursor composition further comprises an additive selected from the group consisting of diepoxides, diisocyanates, diisothiocyanates, and combinations thereof.
 19. The composition of claim 1, wherein crosslinking is effect by heating above 200° C.
 20. The composition of claim 1, wherein crosslinking is effected by actinic radiation.
 21. A device including an optical waveguide comprising the composition of claim
 1. 22. The device of claim 21, wherein the optical waveguide comprises a core that includes the composition of claim
 1. 23. The device of claim 21, wherein the optical waveguide comprises a clad that includes the composition of claim
 1. 24. The device of claim 21, wherein the optical waveguide comprises a core and a clad, both of which comprise the composition of claim
 1. 